Referring to FIGS. 1 and 2, a conventional socket wrench 10 contains a toothed holder 11 accommodated on one end thereof, and the toothed holder 11 includes a polygonal groove 111 defined therein, the polygonal groove 11 of the toothed holder 11 has a slot 112 arranged therein to retain a C-ring 12. Furthermore, a socket tool 20 has a hexagonal fitting segment 201, and the hexagonal fitting segment 201 has a plurality of notches 202 formed on plural corners thereof, such that when the hexagonal fitting segment 201 of the socket tool 20 fits with the polygonal groove 111 of the toothed holder 11, the C-ring 12 retains with the plurality of notches 202 of the socket tool 20, thus avoiding the socket tool 20 removing from the polygonal groove 111 of the toothed holder 11.
However, the C-ring 12 cannot retain with the plurality of notches 202 of the socket tool 20 fixedly, and the socket tool 20 removes from the socket wrench 10 easily.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.